A painter working at 100 feet from the ground, drops his paint brush onto the street below. The function,
s(t)=-16t^2+100, gives the height(in feet) of the paint brush as it falls to the ground. The velocity at time t=2 seconds is given by

lim s(2)-s(t)/2-t
t-->2

Evaluate this limit to find the velocity of the paint brush at 2 seconds. (include units in your answer).